The testing of motor vehicles in accordance with requirements of the United States Environmental Protection Agency and state and local regulatory bodies requires a battery of tests to be performed, with the associated analysis of significant amounts of data. Often, this data is to be compared to limits or guidelines for determination as to whether or not the operating parameters of the vehicle fall within specification. While the use of automated data processing equipment, such as computers, has made the task of obtaining, processing and analyzing such data less burdensome, there remain test procedures which do not provide the needed analysis of data to fully identify potential problems.
For example, inspection and maintenance procedures mandated by the Environmental Protection Agency in response to the Clean Air Act of 1990 require an analysis of exhaust gases of motor vehicles, pursuant to procedure I/M240. The analysis is to include tailpipe testing in a manner which utilizes the use of an inertia flywheel dynamometer to reproduce road driving conditions for the vehicle under test. The emission levels of various exhaust components is measured as a variety of driving conditions is simulated. The overall emission of the components as a proportion of the total exhaust gases is then compared to a reference and a pass/fail decision reached. With sufficient resolution, out-of-specification vehicles can be identified effectively.
The failed vehicle is then typically scheduled for repair to bring the exhaust component readings into compliance. Since the test results often are only in the form of a pass/fail report, however, the mechanic is often ill-equipped to identify and locate the problem. Further testing is normally required.
Even in situations where the underlying data is made available to repair personnel, current methodologies and procedures are not adapted to allow a meaningful analysis to be made. The volume levels of the constituents alone usually provide scant clues as to the source of the problem. Further testing is normally still required.
It is accordingly the purpose of the present invention to provide a method for analysis of vehicle exhaust component test data and similar information in a manner which allows the repair mechanic to identify specific aspects of the test procedure results which do not conform to accepted standards, apply such discrepancies to isolate potential problems which would cause such results, and to allow identification of likely solutions to correct the failure resulting in the recorded results.